Raman spectroscopic investigations on HDO, solved in H2O, on HDO in aqueous potassium iodide solutions, and on pure H2O up to 4000C and 5,000 bar

The OD valency Raman bands of HDO in H2O and in aqueous potassium iodide solutions with 1.8, 4.3 and 13.2 mol% KI as well as the OH valency Raman bands of H2O were measured at temperatures of 25 to 4000C and densities of 0.015 to 1.15 gcm-3. The laser beam of an argon ion gas laser of wavelength 4,880 A polarized in the X-Z plane enters the high-pressure high-temperature Raman cell along the Z axis and is scattered on the molecules of the measuring substance. The light scattered in the Y direction is projected with the lense onto the spectrograph entrance slit. A photomultiplier in the focal plane of the spectrograph scans the scattered light split up into its spectral parts and gives intensity proportional voltage values to a recorder. The Raman bands obtained can be split into gauss-shaped part-bands of which one must assign one to the hydrogen bonded molecules and the other to free molecules. One can thus consider the liquid water as a mixture of the hydrogen bonded and the non-bonded water molecules. The hydrogen bonding energy was determined to be 2.35 +- 0.2 kcal/mol. (HK)